Attachment for motion-picture-projecting apparatus



A. R. SHOEMAKER ET AL ATTACHMENT FOR MOTION PICTURE-PROJECTING APPARATUS Filed May 11, 1922 3 Sheets-Sheet 1 A TTORNEY.

Dec. 1924- 1,519,064

- A. R. SHOEMAKER ET AL:

ATTACHMENT FOR MOTION PICTURE PROJECTING APPARATUS 3 Sheets-Sheet 2 Filed May 11, 1922 -J. E liasen/iazn JVENTORS I ATTORNEY.

A: R. SHOEMAKER ET AL ATTACHMENT FOR MOTION PICTURE PROJECTING'Y'FAPPARATUS Filed May 11, 1922 3 Sheets-Sheet 3 A.RS710emake21..m

IN VEN TORS A TTORNEY Patented Dec. 9, 1924. I

NITED STATES PATENT OFFICE.

AIN'IE R. SHOEMAKER AND JOHN F. HASENKAMP, F GHATTANOOGA, TENNESSEE.

ATTACHMENT FOR MOTION-PICTURE-PROJEGTING- APPARATUS.

Application filed May 11,

To all whom it may concern:

Be it known that we, ALvIn R. SHOEMAKER and J OHN E. HAsnNKAMP, citizens of the United States, residing at Chattanooga, in

the county of Hamilton and State of Tennessee, have invented certain new and useful Improvements in an Attachment for Motion- Picture-Projecting Apparatus, of which the following is a specification.

This invention has reference to an attachment for motion picture apparatus to provide means for protecting. films in motion picture projecting machines from damagein the event of the breaking of the film and from the effects of fire.

When the film breaks in the ordinary projecting machines, or the take up fails to work, orthe machine loses the loop entirely, the invention provides for the contact points of the machine to close the circuit which has been previously opened, thereby automati cally causing the closing-of the fire shutter and cutting off access of the light to the film and breaking the circuit through the main line.

In accordance with the invention, the device is of smaller extent, is more accurate, is very compact, is betterlocated on the machine, is simpler, more certain in its action, automatically cuts off current to the motor and coil, the power consumption is very small, it works when the loop is lost entirely or the take-up fails to work or the film breaks, or strips the sprocket holes, and is absolutely safe. I

Safety devices, of which these applicants are aware are based on operation by hand or by the machine being stopped; Such devices have numerous objections from which the present invention is entirely free.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding however that the invention is not confined to any strict conformity with the drawings,

but may be changed and modified so long as such changes and modifications mark no ma-- terial departure from the salient features of the invention as expressed in the appended claims.

ferred to,

1922. Serial No. 560,092.

In the drawings Figure 1 is a more or less diagrammatic view of a projecting lantern equipped with the invention,

Fig. 2 is a longitudinal section of the controlling or trip mechanism employed in connection with the invention, I

Fig. 3 is an end elevation taken from one end of the structure shown in Fig. 2,

Fig. 4-is an end elevation takeni-in connection with the other end of the structure shown in Fig. 2,

Fl i'g. 5 is a section on the line 55 of Fig. 6 is asection on the line 6--6 0 Fig. 2,

Figure 7 is a rear elevation of the film control circuit closer. V

Figure 8 is a side elevation of the film trol circuit closer in operative position.

Figure 9 is a View similar to Figure 8 with the film control circuit closer in operative position. 75

Figure 10 is a front elevation of a ring controlled circuitcloser positioned above the circuit closer illustrated in Figure 7 Figure 11 is a section on line 1111, Figure .10.

Fig. 12 is a face view of a shutter employed in connection with the invention, and, Fig. 13 is a diagram illustrating the electric connections. 7

Referring to the drawings and particularly'to Fig. 1, there is shown a lantern 1 with connected film houses 2, 3, respectively, between which the film 4 travels, being fed by toothed wheels 5 in the usual manner.-

The film in passing from one magazine to the other through the machine provides a loop 4 in the film so as to'avoid placing the film under undue tension.

There is also provided a lamphouse 6 with the usual cone-shaped front or light directing tube 7 supporting a shutter 8 and directed toward a lens 9, all as is customary. The shutter 8 is provided with a laterally extending arm 8, pivoted as at 8 to the front 7, and the arm 8' is so set up that I whenit moves downwardl through a shifting means. therefor to be hereinafter rethe shutter 8 will be shifted upwardly to close the cone-shaped front 7.

Erected on a low point of the projecting machine 1 is. a post with inter-pivoted arms 11 and 12, both arms being pivoted to the post 10 on which is arranged a pair of opposed'spaced contact members 13 which are insulated from each other. The arm 11 carries a roller 14 engaging the film 4 so that when the parts are in proper position and the machine is running the roller 14 will sustain the arm 11 out of contact with the contact members 13, but in the event of the film 4 breaking, the arm 12 will gravitate into engagement with the contact members 13 and bridge the space between said members, as well as contacting therewith.

At the upper end of the arm 12, there is secured a roller 15 facilitating the threading ofthe film 4 through the machine.

Carried by the lamp house'6 or other convenient part of the projecting machine is a structure shown in Figs. 2, 3 and '4 and arranged to actuate the cut-off shutter 8.

1 its movement on theshaft by means of a key 24. The armature'23 is provided with a terminal head 25.

Because ofthe longitudinal movement of the armature 23 along the shaft 19, and because of the presence of .the key 24, there is provided a spring 26 on the shaft 19 within the spool 21, thus permitting the armature 23 to have a limited longitudinal movement on the shaft 19.

/ Adjacentto the armature 23 and mounted on the shaft 19 is a normally locked spring 1 controlled pulley inclosing a power transmitting element in the form of a coiled leaf spring 28 fast at one end to the pulley 27 and at the other end to the shaft 19;

Mounted in a groove 29 in the peripheral face of the pulley 27, and made fast to said pulley, is a cable 39 passed over a roller 31 at the end of a post 32 and which is connected to the outer end of an arm 8', as at 30, whereby when the pulley 27 is released the spring 128 will operate to revolve the pulley, under such conditions Winding the cable 30. and elevating the. shutter 8 to closed pm sition.

The pulley 27 is provided with an extended hub which carries a cylindrical block 32' of insulation and the said block 32 is secured to the body of the pulleys 27 by the screws 33.

The block 32 has embedded in its periphery, as well as being secured thereto a segmental contact blade 34 which is engaged by a pair of spaced brushes 35, carried by oppositely extending springs 36 which are housed within and have their upper ends secured to an inclosing casing 37, through the medium of binding posts 40. The casing 37 is provided with a hub 38, which is made fast to the shaft 19 through the medium of a set screw 39.

The. springs 36 tend to maintain the brushes into electrical contact with the plate 34 and when in such contact close what may be termed a film shifting miotor circuit. Carried by the end of the post 18 are distributing binding posts 41.

In Fig. 13, there is shown a diagram of the electric circuits of the machine. There is shown an electric driving motor 42 to which is coupled two mains 43, 44 which may be coupled to or represent any suitable source of power, say, street mains. One of the mains, includes a switch 45 of appropriate type. i

The main 43 leads to one terminal 46 of the motor 42 and is then connected by a branch conductor 47 to one of the binding posts 41 which is grounded at 48 to the frame of the structure shown in Fig. 2.

The other terminal 49 of the motor 42 is connected by a conductor 50 to another one 7 of the binding posts 41, which, in turn, is connected by a conductor 51 to a brush 35 bearing upon the plate 34, with the circuit continued through a conductor 52 to another one of the binding posts 41 in circuit with the switch 45 and conductor 44.

The ulley 27 is normally locked against the action of the spring 28, by an abutment projecting from one end thereof and abutting against an abutment 53 oran abutment 54 which projects from the armature 'head 25. The abutment 55 is engaged by abutment 53 or abutment 54 when the magnetic coil 22 is de-energized and which permits of the spring 26 forcing the armature 23 towards the pulley 27, whereby the abutment 55 will impact against the abutment 53 or 54, under such conditions preventing the shifting of the pulley through the medium of thespring 28. Vhen the magnetic coil 22 is energized, due to the closing of its circuit, by the arm 11 engaging the contact members 13, the armature 23 will be drawn away from the pulley 27, rc

leasing the same, under such conditions the.

spring 28 will shift the pulley, thereby winding the cable 30 thereon and elevate the shutter 8 to closed position. When the pulley 27 is actuated by the spring 28, the plate 34 is shifted clear of the brushes under such conditions opening the film shif ing motor circuit whereby any further shifting of the film will be stopped.

' jecting apparatus When the magnetic pull on the armature 1s suflicient 1t overcomes the sprlng 26,

whereupon the block 53 and 54 is released parts are all returned to normal The film 4 is normally engaged by a roller 56 carried by a bent or curved spring arm 57 (see Figs. 1, 10, 11 and 13) so that on the breaking of the film the roller 56, which is of metal, will electrically contact with the machine and complete a circuit by way of a conductor 58 to the contact 13 and conductor 59 to one of the binding posts 41 to a suitable source of current. The spring 57 includes a bridge piece 60 (see Fig. 11) to prevent metallic contact and consequent short circuit.

What is claimed is 1. An attachment for motion picture projecting apparatus comprising normally closed circuit connections for a film shifting .motor, a normally locked shutter shifting device-including a rotatable member provided with a contactual element normally engaging with said connections for closing the film shifting motor circuit when the device is locked and further including a resilient element to rotate said member for shifting the shutter to closed position and for shifting said contactual element to open said circuit when said device is released, a

magnetic device including spring controlled means engaging with and locking said shutter shifting device from actuation when the magnetic devlce 1s de-energized, circult forming means for said magnetic device,

and a film controlled means for closing the circuit to said magnetic device when the film breaks to energize the magnetic device to release the shutter shifting device to provide for the actuation of said rotatable memher, the spring controlled means of said magnetic device provided with abutments engaging with said shutter shifting device for locking the latter when the magnetic device is de-energized. i

2. An attachment for motion picture procomprising normally closed circuit connections fora film shifting motor, a normally locked shutter shifting device including a rotatable member provided with a contactual element normally engaging with said connections for closing the film shifting motor circuit when the device is locked and further including a resilient element to rotate said member for shifting the shutter to closed position and for shlfting said contactual element to open said circuit when said device is released,

circuit when said device is released, a magnetic device including spring controlled means engaging with and locking said shutter shifting device from actuation when the magnetic device is de-energized, circuit forming means for said magnetic device, and a film controlled means including a pivoted element normally retained by the film clear of said circuit forming means and engageable when the film breaks with said circuit forming means to close the circuit for said magnetic device to energize the latter to release the shutter shifting device thereby providing for the actuation ofsaid rotatable member, the spring controlled means of said magnetic device provided with abutments engaging-with said shutter shifting device for locking the latter when the magnetic device is de-energized.

3. An attachment for motion picture projeeting apparatus comprising normally closed circuit connections for a film shifting motor, a normally locked shutter shifting device including a rotatable member pro vided with a contactual element normally engaging with said connections for closing the film shifting motor circuit when the device is locked and further including a resilient elements to rotate said member for shifta ing the shutter to closed position and for shifting said contactual element to open said circuit when said device is released, a magneticv device including spring controlled means engaging with and locking said shutter shifting device from actuation when the magnetic device is de-energized, circuit formmg means for said magnetic device, and a film controlled means for closing the circuit to said magnetic device when the film breaks to energize the magnetic device to release the shutter shifting device to provide for the actuation of said rotatable member, the

spring controlled means of said magnetic device and said shutter shifting device having cooperating means for locking the latter when the magnetic device is de-energized.

4. An attachment for motion picture projecting apparatus com-prising normally closed circuit connections for a film' shifting motor, a normally locked shutter shifting device including a rotatable member provided with a contactual element normally engaging'with said connections for closing the film shifting motor circuit when the device is locked and further including a resilient element to rotate said member for shiftingtheshutter to closed position and for shifting said contactual element to open said a magnetic device including spring controlled means engaging with and locking said shutter shifting device from actuation when the magnetic device is de-energized, circuit forming means for said magnetic device, and a film controlled means including a pivoted element normall retained by the film clear of said circuit orming means and engageable when the film breaks with said circuit forming means to close the circuit for said magnetic device to energize the latter to release the shutter shifting device thereby providing for the actuation of said rotatable member, the spring controlled means of said magnetic device and said shutter shifting device having cooperating means for lccking the latter when the magnetic device is'de-energized.

In testimony whereof, we affix our signatures hereto.

ALVIE R. SHOEMAKER. JOHN F. HASENKAMP. 

